diff --git a/da_detector.py b/da_detector.py
old mode 100644
new mode 100755
index 72f69b5..b21d235
--- a/da_detector.py
+++ b/da_detector.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 """
 this file holds a class, which implements a "detector" - language classifier -
 that learns from predefined, frequency-analysed sets of ngrams